Combination Prism Array for Focusing Light

• US 20170139213A1
• Filed: 02/01/2017
• Published: 05/18/2017
• Est. Priority Date: 10/25/2015
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Oculus VR, LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Schmidtlin, Edouard G. H.
• Granted Patent: US 10,416,454 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02B 3/0043 Inhomogeneous or irregular arrays, e.g. varying shape, size, height
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors

Abstract

A beam deflection device includes two arrays of prisms. The prisms in the first array of prisms have an apex angle below a critical angle such that light passes through the prism and is deflected at an angle below a specified angle. The prisms in the second array of prisms have an apex angle above the critical angle such that light that enters the prism will reflect off the apex surface to an exit surface, resulting in the light being deflected at an angle above the specified angle. In some embodiments, the prisms in the first array and the second array work in conjunction to direct light from multiple locations to a single focal point.

Claims

1. A beam deflector device, comprising:

a single integrated substrate that has a planar entrance surface and a non-planar exit surface, wherein the single integrated substrate includes, on the non-planar exit surface;

a first array of light-steering components, a respective component of the first array of light-steering components located at a respective distance less than a predefined distance from a reference point and the respective component of the first array of light-steering components comprising an optical prism having an apex angle that is less than a critical angle, wherein the first array of light-steering components includes a first prism having a first apex angle and a second prism having a second apex angle that is distinct from the first apex angle; and

a second array of light-steering components, a respective component of the second array of light-steering components located at a respective distance greater than the predefined distance from the reference point and the respective component of the second array of light-steering components comprising an optical prism having an apex angle that is greater than the critical angle.

2. The beam deflector device of claim 1, wherein:

the second array of light-steering components includes a third prism having a third apex angle that is distinct from the first apex angle and the second apex angle and a fourth prism having a fourth apex angle that is distinct from the first apex angle, the second apex angle, and the third apex angle.

3. The beam deflector device of claim 2, wherein:

the first prism, the second prism, the third prism, and the fourth prism are configured to steer at least a portion of light passing through the planar entrance surface toward a common focal point of the beam deflector device.

4. The beam deflector device of claim 1, wherein:

the first array of light-steering components and the second array of light-steering components are configured to steer a portion of light passing through the planar entrance surface toward a common focal point of the beam deflector device.

5. The beam deflector device of claim 1, wherein:

the beam deflector device is configured to focus collimated light entering the beam deflector device through the planar entrance surface toward a common focal point of the beam deflector device.

6. The beam deflector device of claim 1, wherein:

each component of the first array of light-steering components has an apex angle that is different from an apex angle of any other component of the first array of light-steering components; and

each component of the second array of light-steering components has an apex angle that is different from an apex angle of any other component of the second array of light-steering components.

7. The beam deflector device of claim 1, wherein:

the apex angle of the respective component of the first array of light-steering components is defined by the planar entrance surface and an apex surface that is distinct from the planar entrance surface;

the respective component of the first array of light-steering components is configured to allow light entering the respective component through the planar entrance surface to exit from the respective component through the apex surface;

the apex angle of the respective component of the second array of light-steering components is defined by the planar entrance surface and an apex surface that is distinct from the planar entrance surface; and

the respective component of the second array of light-steering components is configured to allow light entering the respective component through the planar entrance surface to internally reflect from the apex surface of the respective component.

8. The beam deflector device of claim 7, wherein the apex surface is a planar surface.

9. The beam deflector device of claim 7, wherein:

the respective component of the second array of light-steering components has an exit surface that is distinct from the planar entrance surface and the apex surface; and

the respective component of the second array of light-steering components is configured to allow light entering the respective component through the planar entrance surface to exit, after internal reflection from the apex surface of the respective component, from the respective component through the exit surface.

10. The beam deflector device of claim 9, wherein:

the apex angle of each component of the first array of light-steering components is selected to steer a portion of light entering the respective component of the first array of light-steering components toward a common focal point of the beam deflector device; and

an exit surface angle, defined by the exit surface and the apex surface, and the apex angle of each component of the second array of light-steering components are selected to steer a portion of light entering the respective component of the second array of light-steering components toward the common focal point of the beam deflector device.

11. The beam deflector device of claim 1, wherein each component of the first array of light-steering components is arranged radially from the reference point and each component of the second array of light-steering components is arranged radially from the reference point.

12. The beam deflector device of claim 1, wherein each component of the first array of light-steering components is an annular prism and each component of the second array of light-steering components is an annular prism.

13. The beam deflector device of claim 1, wherein the first array of light-steering components and the second array of light-steering components are arranged linearly from the reference point.

14. The beam deflector device of claim 13, wherein:

the first array of light-steering components and the second array of light-steering components are arranged linearly in two opposing directions from the reference point so that the reference point is located between a prism of the first array of light-steering components and a corresponding prism of the first array of light-steering components and between a prism of the second array of light-steering components and a corresponding prism of the second array of light-steering components.

15. A display device, comprising:

a two-dimensional array of pixels, wherein each pixel is configured to output light so that the two-dimensional array of pixels outputs a respective pattern of light; and

the beam deflector device of claim 1 configured to transmit the respective pattern of light from the two-dimensional array of pixels.

16. The display device of claim 15, wherein the display device is a head-mounted display device.

17. The display device of claim 15, further comprising:

a two-dimensional array of lenses located between the two-dimensional array of pixels and the beam deflector device.

18. The display device of claim 17, wherein:

the two-dimensional array of lenses is configured to collimate light from the two-dimensional array of pixels.

19. The display device of claim 17, wherein:

the two-dimensional array of lenses includes a two-dimensional array of lens assemblies;

the two-dimensional array of lens assemblies includes a first group of multiple lens assemblies of a first magnification and a second group of multiple lens assemblies of a second magnification that is distinct from the first magnification;

the first group of multiple lens assemblies of the first magnification includes;

a first lens assembly, and

a second lens assembly that is distinct and separate from the first lens assembly;

the second group of multiple lens assemblies of the second magnification includes;

a third lens assembly that is distinct and separate from the first lens assembly and the second lens assembly; and

a fourth lens assembly that is distinct and separate from the first lens assembly, the second lens assembly, and the third lens assembly; and

each of the first lens assembly, the second lens assembly, the third lens assembly, and the fourth lens assembly includes two or more lenses; and

a spatial light modulator configured to selectively reduce transmission of light for the two-dimensional array of lens assemblies.

20. A method, comprising:

outputting a respective pattern of light from a two-dimensional array of pixels; and

transmitting the respective pattern of light through the beam deflector device of claim 1.